1. Technical Field
Various embodiments relate to a semiconductor memory apparatus, and more particularly, to a fabrication method of a resistance variable memory apparatus.
2. Related Art
Nonvolatile memory apparatuses may include a ferroelectric random access memory (FeRAM), a magnetic RAM (MRAM), a phase-change RAM (PRAM), a resistive RAM (ReRAM), a polymer RAM (PoRAM), and the like according to a structure of a unit memory cell or a type of data storage material.
Among the nonvolatile memory apparatuses, the resistance variable memory apparatus such as, a PRAM or ReRAM is a storage apparatus in which a data storage material layer is interposed between a pair of electrodes, and data is stored by changing a resistance state of the data storage material layer through application of a current or voltage.
The resistance variable memory apparatus is in the spotlight as a next-generation memory apparatus in which advantages such as, low cost, random access, high speed operation, low power consumption, and non-volatility are merged.
PRAMs use a phase-change material as a data storage material. When data is written in a PRAM, an access device is driven through a word line. When a current path is formed along the data storage material through a bit line, a state of the phase-change material is changed from a crystalline state (a low-resistance state) to an amorphous state (a high-resistance state) or vice versa.
Demands for high integration and miniaturization of the semiconductor memory apparatus have continued. The resistance variable memory apparatus such as, the PRAM is also required to meet such requirements. Therefore, there is a need for technology for forming a resistance variable memory apparatus with ultra-high thinning, ultra-miniaturization, high yield, and high reliability.